Leptoquarks at $eγ$ Colliders

We consider single production of leptoquarks (LQ's) at $e\gamma$ colliders, for two values of the centre-of-mass energy, $\sqrt{s}=500$ GeV and 1 TeV. LQ's with masses essentially up to the kinematic limit can be seen, even for couplings as weak as $O(10^{-3})$-$O(10^{-2})\alpha_{em}$. It is possible to detect LQ's of mass greater than $\sqrt{s}$ by looking for signals of virtual LQ production in $e\gamma\to e q{\overline q}$.